Every pet parent understands the importance of giving rabies vaccines to their dogs. Rabies is a highly contagious disease and affects many animals, not only dogs, while it is easily transmitted via a scratch or bite. Luckily, proper vaccination is enough to prevent them.

According to the American Animal Hospital Association (AAHA), all dogs should be vaccinated unless they have a medical reason not to. However, although vaccines are essential both for your furry friend’s health and safety, as well as public health, they also carry specific side effects and risks due to this immune system stimulation.

Fortunately, those side effects are usually insignificant, and severe reactions are rare. Still, it is normal for dog parents to feel anxious and informed about how to keep their pets comfortable. The following article will show all the possible rabies vaccine reactions in dogs and ways to help your furry friends if they experience them.

Dog on fence
Dog on fence

What is the Rabies Vaccine?

Vaccination against rabies is very safe for most dogs, and years of extensive testing have proven it to be effective in preventing fatal diseases. Even though no vaccine is 100% secure, rabies vaccines are very effective and immunogenic, and the benefits of these vaccines far outweigh the risks. Take comfort in the fact that you’re protecting your pet from a deadly virus.

With that said, rabies vaccines have been used for decades, and serious problems are rare. Common reactions to the dog rabies vaccine typically include pain, redness, or swelling, which subside within a few days, while some dogs may have a slight fever, reduced appetite, or a temporary lethargic state. There is no need to worry about these side effects, as they usually subside within a few days.

These are known as core vaccines designed to protect against diseases endemic in a region, of potential public concern, legally required to be virulent/highly infectious and carry a risk of severe infection.

Depending on national legislation and the type of vaccine, your dog should receive a booster every 1 to 3 years.

Common Side Effects

Every vaccine, including the rabies vaccine, may cause some side effects or adverse reactions in dogs. Luckily, the most frequent side effects are minor and short-lived, while severe reactions are infrequent. Besides, some dogs won’t experience any side effects at all, but be aware that the side effects typically begin within an hour of vaccination and vanish within one or two days.

These are some of the most common side effects of rabies shots in dogs:

  • Potential soreness, swelling, or redness at the vaccination site: It is common for your furry friends to experience these symptoms after the injection, which can last a couple of days. You can help it by applying an ice pack wrapped in a cloth or any other cold compress to reduce inflammation.
  • Low-grade fever: Another unusual side effect is a low fever of around 100°F that lasts for a day or two. If you want to try to lower it, you can give your dog an over-the-counter medication.
  • Fatigue or lethargy: Some dogs also experience lethargy or fatigue and decreased activity levels for a day or two.
  • Loss of appetite: While some dogs experience an appetite decrease, others may lose interest in food for a short time.
  • Diarrhea or vomiting: Mild digestive upset is also normal immediately after taking the vaccine and should be gone in a couple of days. This is usually self-limiting, but reach out to your vet if symptoms are severe or last more than a few days.
Young woman teaching her black dog obedience gesturing with her finger for it to sit or stay, close up of her hand and the animals head

Recognizing Serious Reactions

If you notice your dog experiencing severe or life-threatening manifestations after receiving a vaccine, seek emergency vet care instantly. Although severe adverse reactions are rare, they might develop within minutes to hours after vaccination.

When to worry about vaccine side effects? These are the symptoms you shouldn’t ignore:

  • Rash, hives, or patchy skin: You may notice your dog scratching excessively. If there is redness or itching, especially on the face or ears, react.
  • Swelling of the lips, eyelids, neck, or even the whole face may quickly become extreme and block airways or blood flow.
  • Diarrhea or vomiting: While these symptoms are typical, a bloody or severe reaction may lead to dehydration if not treated immediately.
  • Trouble breathing or collapse: If your dog acts weak, unsteady, cannot stand up, or is wheezing, gasping, or panting excessively, call your vet immediately.
  • Fever over 103.5°F that lasts more than 24 hours: Although a mild fever is normal, high fevers can indicate an infection and should be monitored closely.

Lethargy or decreased appetite for more than a day: Although sleepiness or loss of appetite for a short time after vaccination is expected, you must call your vet if these symptoms persist or your dog seems highly depressed or weak.

Managing Mild Reactions

Managing rabies vaccine side effects, when mild, is easy and consistently effective.

Mild fever that lasts up to 24 hours, soreness, loss of appetite, or lethargy can usually be managed at home. However, it is always safe to consult your vet, especially if symptoms last more than a few days.

Cold compress for about 15 minutes a few times daily is an excellent way to relieve swelling or redness at the injection site. This can also be solved with an over-the-counter pain medication like baby aspirin or Benadryl, but only by consulting your vet.

Mild fever calls for plenty of water and limited activity. If the fever persists or goes higher, contact your vet.

Lethargy or decreased appetite for a day or two immediately after vaccination is usually not concerning and should be left to resolve on its own. This is only your dog’s immune system response to the vaccine. However, if your dog is not eating, drinking, or having regular bathroom habits after 48 hours, that could indicate a more severe reaction, so call your vet right away.

Observing your dog closely for several days after vaccination is always a good idea. A symptom and recovery log can give your veterinarian important information, especially for future vaccinations. Call your veterinarian immediately if you’re concerned about your dog’s health or behavior.

beautiful female dog laying in car between front seats

Prevention and Preparation

While we have seen the post-vaccination care for dogs, it is also essential to familiarize ourselves with how to prevent severe side effects. The most effective way to minimize risks is to have your dog vaccinated by a vet, avoid unnecessary boosters, and consider blood titer testing to determine if revaccination is genuinely needed.

These are a few things you can do:

Firstly, and most essentially, ensure your furry friend is in good health before getting its rabies vaccine. If your dog is feeling under the weather or has a fever or infection, delay the vaccine until they recover. Its immune system will better handle the vaccine when it’s healthy.

If you want to be prepared, just in case, you can ask your vet about antihistamines. Some vets may recommend Benadryl or the like before the vaccine to reduce the chance of an allergic reaction.

Lastly, make sure your pet is calm and comfortable after the vaccine. Limit activity and walks for a day or two so they can rest, and give them extra love and belly rubs.

Long-term Effects and Safety

The rabies vaccine has been used for decades and is considered safe for most dogs. While some dogs may experience several mild effects that resolve quickly, severe long-term effects of rabies vaccine are extremely rare.

Soreness, redness, or swelling at the injection site are the most common ones, while dogs may also develop immune-mediated diseases like immune-mediated hemolytic anemia on rare occasions.

This is why you should consult your vet to advise you on the likelihood of risks based on your dog’s age, size, and health. If your dog is anxious and fearful, your vet may suggest giving it sedatives or antihistamines to calm it down.

Although we cannot claim any vaccine to be completely safe, rabies vaccine has more benefits than risks. Since rabies is a fatal disease, vaccination is essential to protect your furry friend.

Lastly, it is best to constantly monitor your dog for any unusual symptoms in the weeks following vaccination and report them to your vet immediately. Luckily, in many dogs, there are no side effects or just minor discomfort that resolves quickly.

labrador retriever sitting between owners legs in front seat

Breed-Specific Considerations

Not all dogs react the same to vaccines, and several factors, such as breed and age, affect the potential rabies vaccine allergies in dogs.

Some breeds are more likely to experience adverse reactions from the rabies vaccine, such as small dogs like Poodles, Dachshunds, and Chihuahuas. The vaccine dose can represent a higher concentration for their small size. If you are curious about what is considered a small dog, don’t forget to check out our related article.

Moreover, Sighthounds such as Greyhounds, Whippets, and Salukis seem more likely to experience inflammation or allergic reactions, while Bulldogs, Pugs, and other brachycephalic breeds’ short muzzles and airway structures may increase the risk of respiratory symptoms.

Regarding age, puppies under 12 weeks may be more susceptible to side effects as their immune systems are still developing. Senior dogs over eight years of age can also have a more increased risk of negative reactions due to a weakening immune system.

To prevent any potential side effects, it is essential to note your dog’s size, age, and breed with your vet. What’s more, you should always inform them of your dog’s prior reaction history so they can recommend some steroids or any other medication to prevent any possible reactions.

A vet may also advise a titer test to check if another rabies booster is really needed based on antibody levels.

Aftercare and Monitoring

There are many signs of vaccine reaction in dogs, which is why you should constantly monitor them closely for a few days, even up to a week, for any possible side effects.

Firstly, you should look for swelling, redness, or soreness at the injection site, and then, if there is any, start applying cold compresses. Benadryl, or any other pain medication prescribed by a vet, can also be given, but if these side effects persist for many days or worsen, it’s time to visit your vet!

Observe your canine companion for signs of fever, shivering, or appetite loss. While a mild fever is common and should pass within a day or two, a higher fever or a not-passing one is a sign to call your vet.

Watch your furry friend for behavior changes, including difficulty breathing, seizures, or even excessive drooling. These symptoms are rare, but they require an immediate reaction.

Lastly, limit movement and interaction with other animals during recovery. Shorten your walks and avoid rough play or interaction with unknown dogs. This will lessen your dog’s immune system stress as its body develops an immune response to the vaccine.

Any type of side effects will be addressed properly if you take a bit of time to closely monitor your pet after their rabies vaccine.


All things aimed to help will usually have side effects as well because they are unfamiliar things that enter your or your dog’s body and get the immune systems to react immediately.

Don’t worry; it is most likely that your canine friend will only experience some redness, soreness, or mild fever for one day, which will come as no surprise since now you know what to expect.

Still, continue to monitor your dog closely for the first few days just to make sure everything is okay, or call a vet if you notice anything concerning. Your dog’s well-being and security should always be a priority.

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